EP1762737A2 - Hydrodynamic coupling - Google Patents

Abstract

The coupling has a primary paddle (2), and a secondary paddle (3) that forms a working chamber (4). A flow circuit influencing unit is providing for influencing flow of a working circuit, and a throttle disk (11) is arranged in an area of a parting plane between the primary and secondary paddles. The unit has another throttle disk (12) that is arranged downstream of the former disk. The latter disk has an outer diameter that is larger than an inner diameter of the working chamber and is axially displaceable between two positions.

Description

The invention relates to a hydrodynamic coupling, in detail with the features of the preamble of claim 1.

Hydrodynamic couplings are known in a variety of prior art designs. These generally include a primary impeller and a secondary impeller and act as a speed converter between a drive and an output. The primary blade wheel and the secondary blade wheel thereby form a working space, which is preferably toroidal in design and which can be filled with operating fluid. For a certain degree of filling, the hydrodynamic coupling is characterized by a specific characteristic curve over the entire slip range. If there is an additional active change, map areas can be overshadowed. However, it is often not possible in high-slip areas to meet the requirements of a drive machine. In particular, the torque absorption by the hydrodynamic coupling is too high in these slip regions. For this purpose, measures are known from the prior art in order to reduce the torque absorption at high slip. The most common means is the installation of a so-called throttle disk, which extends from the axis of rotation in the working space, into use. The throttle disk is assigned to one of the two paddle wheels and at least downstream of the exit from the Sekundarschaufelrad or upstream of the entry into the Primärschaufelrad. The outer diameter of the throttle disk is characterized by a larger diameter than the inner diameter of the working space in the region of the parting line. The provision of the throttle plate makes it possible to make an influence on the flow circuit, especially at high slip in the range between 100 and about 70%, since this builds up in this area substantially in the region of the inner diameter. This reduces the torque which can be absorbed by the hydrodynamic clutch compared with a design without a throttle disk. Further are In general, further measures are known to influence the transmission behavior of a hydrodynamic coupling during operation or in different slip states. These measures are essentially characterized in that either the change in the degree of filling is actively controlled or additional internals are effective. A major disadvantage of an embodiment with such a fixed throttle plate is that only an influence during the start-up process, that is, in the range of very high slip, usually between 100 and 70%, is given. With increasing reduction of the slip, the influence is reduced, since a stable flow circuit above the throttle plate is formed and thus can no longer actively influence the flow circuit.

The invention is therefore based on the object to further develop a hydrodynamic coupling of the type mentioned above, that over the entire operating range, that is at any slip state high - and low slip, influencing the transmission behavior, in particular a reduction in torque absorption possible is, The solution of the invention should be characterized by a low design and control engineering effort.

The solution according to the invention is characterized by the features of claim 1. Advantageous embodiments are given in the subclaims.

A hydrodynamic coupling with a primary blade wheel and a secondary blade wheel, which form a working space which can be filled with operating medium and which is assigned a resource supply system, has means for influencing the flow circuit. According to the invention, these comprise an orifice plate fixedly assigned to a paddle wheel, which is arranged in the region of the parting plane between the primary paddle wheel and the secondary paddle wheel, and either the exit from the secondary paddle wheel is downstream or upstream of the entry into the Primärschaufelrad. Furthermore, the hydrodynamic clutch comprises a further second throttle disk which, viewed in the axial direction from the secondary bucket wheel to the primary bucket wheel, is arranged downstream of the first throttle disk and is displaceably mounted thereon, and thus also the primary bucket wheel. The first throttle disk extends in each operating state into the working space, preferably this is designed as a flat disk-shaped element, which is arranged parallel to the parting plane and has an outer diameter which is greater than the inner diameter of the working space. Preferably, the first throttle disc is rotatably connected to one of the paddle wheels. The connection is preferably carried out with the secondary or with this rotatably coupled element. Other designs are conceivable, the second throttle plate is mounted axially displaceable relative to the first. The assignment is made to the primary blade wheel, wherein preferably the second throttle disc is mounted axially displaceable on this. The displaceability takes place between a first, also referred to as active position position and a second, also referred to as inactive position and vice versa. The first active position is characterized by a position in the region of the axial extension of the working space between the parting plane and the outermost dimension in the axial direction of the working chamber of the primary blade wheel forming part, wherein here preferably a position in the region of the parting plane T is present, the second inactive Position is characterized by a position of the throttle disk in the region of the boundary of the working space in the axial direction or outside. For this purpose, the second throttle plate preferably assumes a position which is either outside of the working space or at least allows a flush conclusion with this and the second throttle plate forms quasi a wall region of the working space.

The inventive combination of a fixed and an axially displaceable throttle disk, there is the possibility of a characteristic adjustment in the inactive position of the second throttle disk to cause an influence on the flow circuit, but without affecting the characteristic in the active position of the second throttle plate. The second throttle plate can then be used specifically for controlling the transmission behavior, wherein any positions between the first and second position can be taken.

According to the invention, the outer diameter of the second throttle disk is also greater than the outer diameter of the first throttle disk. Thus, in the region of very high slip when the second throttle disk is brought into the active position, an even greater momentum depression, ie reduction of the recordable moment on the primary blade wheel, can take place here as the effect of the first throttle disk alone.

Regarding the structural design of the hydrodynamic coupling and its operating principle, in particular the type of flow - centripetal or centrifugal - there are no restrictions. It is only to ensure that an optimal resource flow is enabled in the resource supply system.

1. a) drehfest mit dem Primärschaufelrad verbunden sein oder aber
2. b) relativ zum Primärschaufelrad in Umfangsrichtung bewegbar sein.

The second throttle plate is axially displaceable relative to the primary, but can

1. a) be connected to the Primärschaufelrad rotationally fixed or
2. b) be movable relative to the Primärschaufelrad in the circumferential direction.

In both cases, however, a relative movement in the axial direction of primary impeller and second throttle plate is possible. Also for the embodiments of the structural design of the rotationally fixed coupling between the throttle disk and the primary blade wheel and ensuring the axial displacement are no restrictions. These couplings can be executed as non-positive or positive connections. In case b), the second throttle plate via an axial and radial bearings on Stored primary impeller. Generally, a non-rotatable mounting is not required, in which case at least one Axialgleitlager is provided.

The first throttle disk and the second throttle disk may be arranged side by side or one behind the other in the axial direction of the hydrodynamic coupling. According to an advantageous embodiment, the first throttle plate is arranged with its extent in the radial direction of the hydrodynamic coupling completely or partially adjacent to the second throttle disk, that is, in a projection of the second throttle disk in the axial direction in the plane of the first throttle disk, the first throttle disk is partially or completely within the projection surface (which extends in the radial direction of the hydrodynamic coupling, perpendicular to the axis of rotation of the hydrodynamic coupling) of the second throttle disk. One could also say, seen in the axial direction, the first throttle plate is partially or completely covered by the second throttle plate. This is shown for example in FIG.

Figur 1

verdeutlicht eine erfindungsgemäße Ausführung einer hydrodynamischen Kupplung;

Figur 2

verdeutlicht anhand eines M/v - Diagramms die sich einstellenden Verhältnisse mit und ohne erfindungsgemäße Ausführung.

The solution according to the invention is explained below with reference to figures. The following is shown in detail:

FIG. 1

illustrates an embodiment of a hydrodynamic coupling according to the invention;

FIG. 2

illustrates on the basis of an M / v diagram the adjusting conditions with and without execution according to the invention.

FIG. 1 shows, in a schematically simplified illustration, the basic structure of a hydrodynamic coupling 1 designed according to the invention in axial section. This comprises a primary wheel 2 and a secondary wheel 3, which together form a working space 4 which can be filled with operating medium. The primary wheel 2 acts as a rule as impeller, and the secondary impeller 3 as a turbine wheel in the power transmission during Use considered in drive trains from the prime mover to the output. The primary impeller 2 is at least indirectly with a drive machine not shown here, that is, directly or indirectly via further transmission elements rotatably connected, while the Sekundärschaufelrad 3 with an output not shown here in detail at least indirectly, that is, either directly or via further transmission elements is connectable , Connectable means that either a permanent non-rotatable connection is provided or even a switchability can be given. In the working space 4, a flow circuit 5 is set during rotation of the primary blade wheel 2. This is shown here by means of an arrow. The hydrodynamic coupling 1 may be a hydrodynamic coupling with a stationary housing or, as shown here, a co-rotating housing in the form of a coupling shell 6. The coupling shell 6 is rotatably connected to the primary blade wheel 2 and surrounds the secondary blade 3 in the circumferential direction completely and partially in the radial direction. The coupling shell 6 can be performed with the primary blade 2 as an integral unit. The hydrodynamic coupling, in particular the working space 4, is, as already stated, filled. For this purpose, the hydrodynamic coupling 1 is assigned an operating medium supply and guide system 9. This is coupled to at least one inlet 7 and an outlet 8 from the working space. Depending on the type of flow through the hydrodynamic coupling 1 inlet 7 and outlet 8 can be arranged differently. In the case shown, the positions of inlet 7 and outlet 8 are reproduced by way of example in centripetal flow. The inlet 7 is arranged in the region of the parting plane T between the paddle wheels 2 and 3 in the region of the outer dimensions of the working space 4. The outlet 8 takes place in the region of the inner diameter of the working space 4. According to the invention, means 10 for influencing the flow circuit 5 are provided in the working space 4. These include a first throttle plate 11, which is assigned to one of the two paddle wheels - primary paddle wheel 2 or secondary paddle wheel 3 - in the illustrated case the secondary paddle wheel 3 and thus the entry of Flow circuit 5 is arranged upstream of the primary blade 2. The first throttle plate 11 is rotatably connected in the illustrated case with the secondary blade 3. This is arranged in the region of the parting plane T between the primary blade wheel 2 and the secondary blade wheel 3 and extends from the inner diameter d _{l4-3 of} the working space 4 formed on the secondary _blade 3 part of the working space 4 in this. Preferably, the throttle plate 11 is designed such that it is aligned parallel to the parting plane T. The outer diameter d _{A11 of} the throttle _disk 11 is greater than the inner diameter d _{l4 of} the working space 4. This ensures that even with a minimum degree of filling FG _min and high slip yet an additional suppression of the recordable moment M _P on the primary blade 2 is realized. The first throttle disk 11 is effective in the range of the startup of the hydrodynamic coupling 1 at very high slip values between 100% to 70%. This means that in this range of minimum speed ratios ν, that minimum torque which can be absorbed by the hydrodynamic clutch 1, which corresponds to the moment M _P at the primary bucket wheel 2, can be influenced and smaller than theoretically at this fill level FG _min without influencing or the additional ones according to the invention Measures adjusting impulsive moment M _P is. This results in a displacement of the recordable by the primary blade 2 torque M _P toward a target point in the clutch characteristic or pump characteristic in the direction of a low torque in the speed / Drehmornentenkennfeld in the range of high slip values. With decreasing slip, ie equalization of the speeds of the primary impeller 2 and the secondary impeller 3 direction equal speed and with increasing degree of filling in the direction of maximum filling FG _max is in the working space 4 with the first throttle plate 11 a stable flow circuit, the influence of the throttle disk 11th reduced to this with decreasing slip. However, in order to also achieve a characteristic adaptation in normal operation, that is to say also with a larger degree of filling FG> FG _min and lower slip, the means for influencing the flow circuit 10 comprise a further second one Throttle 12, which is also disposed in the region of the parting plane T between the primary blade 2 and the secondary blade 3, the arrangement viewed in the axial direction between the secondary blade 3 and the primary blade 2, the first throttle plate 11 is arranged downstream and the second throttle plate 12 between a first active position I and a second inactive position II and vice versa. The second throttle disk 12 is assigned to the primary blade wheel 2 and mounted on this axially displaceable. The second throttle disk 12 is displaceable in the axial direction between the first active position I, which is characterized by the arrangement of the throttle disk 12 in the axial direction in the region of the parting plane T and a second inactive position II. The second inactive position II is characterized by a position of the throttle plate 12, which is preferably arranged in the axial direction as far as possible in the axial direction of the maximum axial extent of the flow circuit, preferably outside of the flow circuit. The embodiment according to FIG. 1 discloses a primary _{blade wheel} 2 with a region 14 which is free of blading 13 and which is arranged in the region of the inside diameter d _{14 of} the working space 4. In this area 14, the throttle disk 12 is arranged and serves to guide the flow circuit in this area in dependence on the axial position between the positions I and II of the throttle disk 12. The inactive position II is characterized by a position in the region in the axial direction outer dimensions of the working space 4 characterized. The second throttle disk 12 is guided displaceably on the primary blade wheel 2 in the axial direction. Constructively, this can be realized in different ways. In the simplest case, only one sliding pair 15 is provided between the second throttle disk 12 and the primary blade wheel 2. A non-rotatable connection is not required. However, it is also conceivable corresponding positive or non-positive connections that allow a rotationally fixed coupling with simultaneous axial displacement. To shift the throttle plate 12 of this is associated with an adjusting device 16. This can be designed differently, in the simplest case, the displacement is realized under pressure control, that is, the throttle plate 12 is connected to a piston element or forms this, which is acted upon by a pressure medium.

zu gewährleisten, ist eine Drückung des aufnehmbaren Momentes M_P gerade in hohen Schlupfbereichen, dass heißt bei Schlupfwerten zwischen 100 % bis 70 %, erwünscht. Mit der festen Drosselscheibe 11 wird dieses bei Verharren der verschiebbaren Drosselscheibe 12 in der inaktiven Stellung II realisiert. Für einen bestimmten Füllungsgrad FG ergibt sich dann die Kennlinie B. Daraus wird ersichtlich, dass gerade in hohen Schlupfbereichen eine sehr starke Drückung des aufnehmbaren Momentes M_P erfolgt, während diese Drückung in Richtung geringen Schlupfes abnimmt. Demgegenüber verdeutlicht die Kennlinie C die Kupplungskennlinie für den gleichen Füllungsgrad FG mit der axial verschiebbaren Drosselscheibe 12 in der Stellung aktiv. Aus dieser ist eine weitere Drückung des aufnehmbaren Momentes M_P in Bereichen hohen Kupplungsschlupfes erkennbar. Wie bereits ausgeführt, dient die erfindungsgemäße Lösung hauptsächlich der Kennlinienanpassung in der inaktiven Stellung der axial verschiebbaren Drosselscheibe 12, ohne dabei die Kennlinie in der aktiven Stellung der verschiebbaren Drosselscheibe 12 zu ändern. Die in der Figur 2 dargestellten Kupplungskennlinien beziehen sich dabei immer auf den gleichen Füllungsgrad für die einzelnen Kombinationen und unterschiedlichen Stellungen der axial verschiebbaren Drosselscheibe 12. Dabei sind die Kennlinien über den gesamten Schlupfbereich für einen bestimmten Füllungsgrad ohne Änderung der Position der axial verschiebbaren Drosselscheibe 12 aufgenommen. Zusätzlich kann noch eine weitere Beeinflussung der Küpplungskennlinie durch die Verschiebung der Drosselscheibe 12 zwischen ihrer inaktiven Stellung II und ihrer aktiven Stellung I und umgekehrt erzielt werden. Die Ansteuerung der zweiten axial verschiebbaren Drosselscheibe 12 erfolgt dabei im Hinblick auf das Zusammenwirken mit einer Antriebsmaschine und den am Abtrieb zu erzielenden Verhältnissen, wobei dies vom konkreten Einsatzfall abhängig ist. Diesbezüglich wird auf die einzelnen Möglichkeiten der genauen Abstimmung der Aktivierung der verschiebbaren Drosselscheibe 12 hier nicht näher eingegangen.With the inventive combination of a fixed throttle plate 11 and an axially displaceable throttle plate 12 while characteristic adjustments in the speed / torque map can be made so that a large part of desired operating ranges can be covered. The second throttle disk 12 in this case has an outer diameter d _A12 , which is greater than the outer diameter d _{A11 of} the first throttle disk 11. This ensures that, as it were, the second throttle disk 12, in its active position, in which it is positioned in the region of the parting plane T, achieves an even stronger depression of the absorbable moment M _P on the primary blade wheel 2. The characteristic curves achievable with a hydrodynamic coupling 1 embodied according to the invention with a fixed throttle disk 12 and a throttle disk 12 which can be displaced in the axial direction are reproduced in FIG. 2. This illustrates individual clutch characteristic curves on the basis of the speed ratio / torque characteristic diagram. The clutch characteristic A illustrates the recordable torque M _{P of} the hydrodynamic clutch 1 via the speed ratio ν = n _T / n _P with n _T = rotational speed of the secondary blade wheel 3 and n _P = rotational speed of the primary wheel 2. The characteristic curve A illustrates the recordable torque of the hydrodynamic coupling 1 without the fixed throttle disk 11 with only one axially displaceable throttle disk 12 in the inactive position II. This corresponds to a hydrodynamic coupling 1 without means for influencing the flow circuit. In this case, the flow circuit in the working space 4 is not influenced for a given degree of filling FG, so that here in operating areas with high slip a very high, by the hydrodynamic coupling 1 recordable moment M _P results. However, since it is often required to adapt to the corresponding drive machine, the recordable moment M _P in the range of high clutch slip, that is at very low speed ratio $\frac{n_T}{n_P}$

to ensure that the impressing moment M _P is expressed in high slip areas, that means at slip values between 100% to 70%, desired. With the fixed throttle disk 11, this is realized while the displaceable throttle disk 12 is in the inactive position II. The characteristic curve B then results for a certain degree of filling FG. It can thus be seen that a very high pressure of the absorbable moment M _P occurs, especially in high slip regions, while this depression decreases in the direction of low slip. In contrast, the characteristic C illustrates the clutch characteristic for the same degree of filling FG with the axially displaceable throttle plate 12 in the active position. From this a further depression of the recordable moment M _{P can be seen} in areas of high clutch slip. As already stated, the solution according to the invention mainly serves to adapt the characteristic curve in the inactive position of the axially displaceable throttle disk 12, without changing the characteristic in the active position of the displaceable throttle disk 12. The clutch characteristics shown in Figure 2 always refer to the same degree of filling for the individual combinations and different positions of the axially displaceable throttle 12. Thereby, the characteristics over the entire slip range for a certain degree of filling without changing the position of the axially displaceable throttle plate 12 are added , In addition, a further influence on the Küpplungskennlinie by the displacement of the throttle plate 12 between its inactive position II and its active position I and vice versa can be achieved. The control of the second axially displaceable throttle plate 12 takes place in view of the interaction with a prime mover and to be achieved at the output ratios, this being dependent on the specific application. In this regard, the individual options for the exact tuning of the activation of the displaceable throttle plate 12 will not be discussed here.

As already stated, the hydrodynamic coupling 1 can be operated both with centripetal and centrifugal flow. This depends in detail on the connection of the resource supply system 9 to the working space 4 and the structural conditions. Accordingly the inlet 7 and the outlet 8 or the inlet 7 and outlet 8 can be arranged accordingly. When not shown in Figure 1, centrifugal flow, the supply to the working space 4 from the direction of the axis of rotation R of the hydrodynamic coupling 1 in the radial direction to the working space 4 out, preferably via corresponding filling channels in the blading of the hydrodynamic coupling 1 itself, which preferably at the Primärschaufelrad 2 are arranged. The inlet 7 is then preferably arranged in the region of the lowest static pressure. The outlet 8 is then arranged in the radial direction in the region of the outer circumference of the hydrodynamic coupling 1, either in the region of the parting plane T in the region of the outer circumference D _{A4 of} the working space 4 or one of the impellers, preferably the primary impeller. In the case of centripetal flow, as illustrated in FIG. 1, the supply of working fluid takes place in the region of the outer diameter of the working space 4, in particular in the region of the parting plane T between the primary blade wheel 2 and the secondary blade wheel 3 in the gap formed between them. The exit from the working space 4 then takes place in the radial direction inwards to the axis of rotation R, preferably in the region of the parting plane T on the inner circumference d _{l4 of} the working space 4. In this case, the resource is _{supplied in} the _{resource supply} system 9 via so-called Schaufelradnebenräume, for an embodiment shown in FIG an auxiliary space 17, which is formed by the outer periphery 18 of the secondary blade wheel and the inner periphery 19 of the coupling shell 6. The resource removal takes place via corresponding channels on the secondary impeller and between the primary impeller 2 and the secondary impeller 3.

With regard to the execution of the adjusting device 16 for the second throttle disk 12 are no restrictions. In the simplest case, however, resources from the resource supply system 9 is used as a pressure medium. A self-sufficient pressure medium source is also conceivable.

LIST OF REFERENCE NUMBERS

1

hydrodynamic coupling

2

primary blade

3

secondary blade

4

working space

5

Flow circuit

6

coupling shell

7

entry

8th

exit

9

Working fluid supply system

10

Means for influencing the flow circuit

11

first throttle plate

12

second throttle plate

13

blading

14

clear area from the blading 13

15

sliding pair

16

setting device

17

Outbuildings

18

outer periphery

19

inner circumference

T

parting plane

d _A4

Outer circumference of the working space 4

d _l4

Inner circumference of the working space

d _l4-3

Inner circumference of the working space in the region of the secondary blade wheel 3rd

d _A11

Outer circumference of the throttle disk 11

d _A12

Outer circumference of the throttle disk 12th

I

active position of the throttle disk 12

II

inactive position of the throttle 12

Claims (13)

Hydrodynamic coupling (1) 1.1 with a primary impeller (2) and a secondary impeller (3), which form a working space (4) which can be filled with operating material; 1.2 with a resource supply system (9); 1.3 with means (10) for influencing the flow circuit (5) in the working space (4) adjusting working cycle; 1.4 with a throttle plate (11) which is arranged in the region of the parting plane (T) between the primary blade wheel (2) and secondary blade wheel (3), one of the paddle wheels (2, 3) is assigned and the outlet of the flow circuit (5) from the secondary paddle wheel (3) is arranged downstream of or upstream of the inlet into the primary _{blade wheel} (3), wherein the outer diameter (d _A11 ) of the throttle _disc (11) is greater than the inner diameter (d _l4 ) of the working space (4); characterized by the following features: 1.5 the means (10) comprise a second throttle disc (12), which in the axial direction between the secondary blade wheel (3) and the primary blade wheel (2) is arranged downstream of the first throttle disc (11), a larger outer diameter (d _A12 ) than the inner diameter (d _l4 ) of the working space (4) and axially displaceable between a first active position (1) and a second inactive position (II) relative to the Primärschaufelrad (2), wherein the first position by a position in the region of the parting plane (T ) between the primary blade wheel (2) and the secondary blade wheel (3) and the second position (II) is characterized by a position in the region of the axially outer dimension of the primary blade wheel (2). Hydrodynamic coupling (1) according to claim 1, characterized in that the outer diameter (d _A11 ) of the first throttle disc (11) is smaller than the outer diameter (d _A12 ) of the second throttle disc (12). Hydrodynamic coupling (1) according to one of claims 1 or 2, characterized in that the first throttle disc (11) is non-rotatably connected to the secondary impeller (3). Hydrodynamic coupling (1) according to one of claims 1 to 3, characterized in that the second throttle disc (12) rotatably connected to the Primärschaufelrad (2), but axially displaceable with respect to this. Hydrodynamic coupling (1) according to claim 4, characterized in that the connection between the primary blade wheel (2) and the second throttle disc (12) is designed as a positive or non-positive connection. Hydrodynamic coupling (1) according to one of claims 1 to 5, characterized in that between the primary blade wheel (2) or a rotatably coupled thereto element and the second throttle disc (12) at least one sliding pair, to form a Axialgleitlagers is provided. Hydrodynamic coupling (1) according to one of claims 1 to 3, characterized in that the second throttle disc (12) is externally mounted. Hydrodynamic coupling (1) according to one of claims 1 to 7, characterized by the following features: 8.1 the primary impeller (2) has one of the blading (13) free area 8.2 the second throttle disc (12) is arranged in the region free of the blading (13), Hydrodynamic coupling (1) according to one of claims 1 to 8, characterized in that the second throttle disc (12) is associated with an adjusting device (16). Hydrodynamic coupling (1) according to claim 9, characterized in that the adjusting device is formed by a piston connected to the throttle plate (12) or formed by this, which is acted upon by a pressure medium source. Hydrodynamic coupling (1) according to claim 10, characterized in that the pressure medium source is part of the operating medium supply system (9). Hydrodynamic coupling (1) according to one of claims 1 to 11, characterized in that the second throttle disk (12) is arranged in the axial direction of the hydrodynamic coupling (1) adjacent to the first throttle disk. Hydrodynamic coupling (1) according to claim 11, characterized in that the first throttle disc (11) is arranged with its entire extent in the radial direction of the hydrodynamic coupling (1) partially or completely within a surface in the radial direction of the hydrodynamic coupling (1) through the extent of the first throttle disc (11) is covered in the radial direction.

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